Donaldson Comapny, Inc.

The United States of America As Represented by the Secretary of

Donald W Schoen

Jerry J Klug

Thomas J Retka

James M Silvernail

The invention is an air purifying apparatus having an air inlet plenum (22, 140) mounted to a filter canister (21) and containing a bypass (63, 157). A barrier (52, 147) divides the inlet plenum (22, 140) into an inlet chamber (53, 150) and an outlet chamber (54, 151). In one embodiment the bypass is formed as a box (63) attached to the plenum (22) and containing openings (70, 71) which communicate respectively with the inlet chamber (53) and the outlet chamber (54) to define a bypass flow path from the inlet chamber (53), through the box (63) and into the outlet chamber (54). In another embodiment the bypass is formed as an opening (157) in the barrier (147) to allow direct communication between the inlet (150) and outlet (151) chambers. The filter canister (21) containing filters (91, 94) is normally hermetically sealed and is mounted to the plenum (22, 140) to allow air flow from the inlet chamber (53, 150), through the filters (91, 94) and into the outlet chamber (54, 151) when the hermetic seal is destroyed and the bypass flow path is occluded. Actuators (125, 126 or 155, 156) in the plenum (22, 140) are operably connected to closures (100, 101) on the filter canister (21). In a first position, the actuators (125, 126 or 155, 156) maintain the hermetically sealed condition of the filter canister (21). In a second position the actuators (125, 126 or 155, 156) destroy the hermetic seal by removing the closures (100, 101) and create an alternate air flow path through the filters (91, 94). The bypass flow path is occluded upon activation of the actuators either by inversion of the box (63) to close its openings (70, 71) or by valves (161, 162) which are carried on the actuators (155, 156) and which close the bypass opening (157) upon removal of the closures (100, 101).

Air purifier with hermetic sealing

A filter assembly (10) for the filtration of toxic gases from the air is disclosed, which includes a unitized cylindrical housing having oppositely disposed end covers (11, 12), with an inlet port (11a) in one end cover and an outlet port (13a) in the side wall. An annular, pleated filter element (21) extends between the end covers (11, 12) between perforated liners (18, 19), and a third, perforated liner (20) is spaced outwardly from the center or common liner (19) to provide an annular space therebetween which is filled with activated charcoal (27). Fines media (25, 26) are positioned on opposite sides of the activated charcoal (27). The first, pleated filter (21) and the second, charcoal filter (27) are thus mounted contiguous to one another on opposite sides of separating wall (19, 25), and extend between the end covers (11, 12) to provide filtration for air being drawn through the filter unit.

Unitized gas-particulate filter and housing

An auger construction is provided which reduces the surface noise radiated by the auger and serves to at least partially isolate the auger from the remainder of the machine. The auger construction comprises an inner shaft and outer concentric shafts, the latter carrying the helical cutting blade and generally corresponding to the shaft of a conventional auger. An elongated annulus of noise and vibration dampening material is disposed between the inner and outer shafts. Preferably, the outer shaft is isolated from the machine by further noise dampening material disposed between the mounting flange and the proximate end of that shaft and between the free end of the inner shaft and the end of the hose in the outer shaft. A bore in the inner shaft is also filled with noise dampening material. A number of arrangements are disclosed for fixing the two shafts together so as to prevent rotational slippage therebetween.

Auger construction providing reduced noise

A control mechanism for apparatus for cleaning of fluid filters by a jet of fluid directed toward a filter in a direction reversed to that of the flow of fluid to be filtered through the filter element. An elongated manifold extends across the downstream or clean fluid delivery side of the filter element, and has a plurality of aligned apertures extending longitudinally of the manifold and facing the adjacent side of the filter element. A plurality of valve elements are mounted in the manifold for movement toward and away from closing relationship with the apertures, and are yieldingly urged toward closing relationship with their respective apertures. A rotary cam shaft is journaled in the manifold and includes a plurality of cams each associated with a different valve element. A pawl and ratchet arrangement is operative to open each of the valves in succession responsive to movement of the manifold across the side of the filter element. The cam arrangement is such that only one valve element is open at any one given time during the filter cleaning operation.

Growing community of inventors

Saint Paul, MN, United States of America

Donald W Schoen